One study found that bicep activity was far greater in the chin-up than in the pull-up. Bdend-1g /* Trending Now */ /* Center Rail */ #ya-center-rail .profile-banner-default .ya-ba-title #Stencil . Bgc-lgr #ya-best-answer, #ya-qpage-msg, #ya-question-detail, li.ya-other-answer .tupwrap .comment-text /* Right Rail */ #Stencil . Bxsh-003-prpl #yai-q-answer, #ya-trending, #ya-related-questions h2. Fw-300 .qstn-title #ya-trending-questions-show-more, #ya-related-questions-show-more #ya-trending-questions-more, #ya-related-questions-more /* DMROS */ . If you work online, it’s really great to get away from the computer and meet people (we’re talking real life here).This will force you to extend your spine and anteriorly tilt your pelvis as you're extending your shoulder joints, which are also functions of the lats.So pulling your chest to the bar will cover three functions of the lats as opposed to one.